How To Tell If A Diamond Is Real With A Flashlight

Diamonds are one of the most precious and famous gemstones in the world today; the fact that this gemstone is extremely difficult to come by makes it rare and expensive to purchase, especially the one with good quality. These days diamonds can be used in almost everything, but they thrive the most in female fashion and accessories hence the saying ‘a diamond is a girl’s best friend’.

It is also popularly affiliated with wedding or engagement rings which is why when people make purchases for diamond rings, they invest so much time and money to get the real thing because it would carry meaning and value at the end of the day.

With the popularity of fake diamonds, it would be extremely beneficial to know some tips or hacks you could use to check for authenticity in a diamond when making your purchase; most people use the flashlight test, which is quick and easy, but this is only when you do it right, and you know when you’re looking for. So, in this article, I’ll walk you through the proper procedures when using the flashlight test and other easy methods to check for authenticity in your diamond so you’ll always get the real thing.

What Is A Diamond?

A diamond is a gemstone made primarily from carbon atoms arranged in a crystalized structure known as the diamond cubic. They form as carbon atoms under high temperatures and pressure usually present underneath the Earth’s surface; they usually take billions of years to form. The first diamonds were found and mined in India a long time ago, over 2,400 years.

Diamonds live underground, and they can only be acquired through natural occurrences like volcanic eruptions; when volcanic pipes shaped like carrots, also known as kimberlite pipes, push diamonds from underneath to the surface, they cool along the way and are later mined from the ground, cleaned and sold. Mining of diamonds usually takes place in areas that have previously undergone volcanic activities; diamonds are also acquired from ocean floors and gravel beds.

Diamonds are indeed unique gemstones that are not only beautiful but have the highest level of hardness and thermal conductivity than any other natural material in the world; this is what makes them useful in large industries for cutting, drilling, grinding, and polishing tools. Small diamonds are usually attached to the edges or tips of industrial tools.

Diamonds are popularly used in fashion accessories like earrings, engagement rings, necklaces, bracelets, etc., because of the attractive luster and durability it possesses.

Diamonds are also a big part of audio equipment manufacturing; they are found in most DJ equipment and high-quality sound recorders; they elevate the sound quality because of their hardness which makes sounds easily vibrate at high speed.

Types Of Diamonds

When we speak about diamonds, there are different kinds out there, and most people usually consider only the diamond grading attributes, which are the 4 C’s when talking about diamonds; these 4 C’s are the clarity, cut, color, and carats. They are important to note when making a purchase, but diamonds are not only classified with the 4 C’s but also with the physical and chemical properties it contains; this classification makes it possible for gemologists to analyze a diamond’s growth, color, and authenticity. 

This scientific classification is grouped into five types: Type Ia, Type Ib, Type 1ab, Type IIa, and Type IIb. These types of diamonds are grouped mainly by the impurities it contains, like nitrogen and boron, which affects the color of the diamond, but the Type IIa diamonds are devoid of nitrogen or boron, which is why they have a clear and sparkling color; they are the purest and rarest diamonds which are valuable and expensive.

However, to a customer trying to purchase a diamond, the classification is usually centered around these four groups:

  • Natural diamonds refer to the ones we usually picture in our minds when we think about diamonds, colorless and sparkling in the light. As the name implies, these diamonds refer to the real ones that come from the ground and are free from impurities.
  • Lab-grown diamonds- these types of diamonds are often regarded as substitutes for real diamonds; they are almost like the real thing in every aspect with little differences that a regular customer would not notice. They are manufactured with the aid of technology, and the production and distribution of these lab-created diamonds make it less expensive to purchase a diamond.
  • Treated diamonds- these are diamonds that are naturally mined but have been transformed or enhanced artificially to look better for commercialization. These kinds of diamonds are worked on to have a chance in the market, and they end up looking good, and their prices become cheaper.
  • Natural Fancy colored diamonds- these types of diamonds are extremely rare and incredibly beautiful; they are mostly worn by celebrities and come in different colors, especially the pink and canary yellow diamonds, which are very popular. They also come in purple, blue, violet, black, white, black, red, green, yellow, grey, etc.

They are divided into three subgroups: natural colored diamonds, lab-grown colored diamonds, and treated colored diamonds.

Why The Need To Test A Diamond?

A diamond is a beautiful and expensive gemstone is enough reason for you to test your diamond since you’d be investing so much in it. Some other reasons why you should test your diamond for authenticity includes:

– Availability of imitation diamonds

The growth of technology has made it possible for diamonds to be created in labs, and this is a good development because these lab-created diamonds are cheaper and as attractive as the real ones. 

This becomes a problem when diamond sellers take these lab-created ones and sell them for the same price as the natural ones gotten from the ground, which is why you need to know how to spot the differences between natural and lab-created diamonds.

– Use of other gemstones as diamonds

The Earth has filled with numerous other unique gemstones apart from diamonds; they are all incredibly attractive and used in accessories. Some include white topaz, white sapphire, moissanite, and cubic zirconia. They carry a similar appearance and sparkle as diamonds and could be easily mistaken for a diamond if not checked correctly.

Most of them are cheaper than a diamond but could still be sold at the same price, so if you wish to own a real diamond, you must lookout for this when making your purchase.

The 4 C’s In Identifying A Real Diamond

The 4c’s of diamond testing include the cut, color, clarity, and carat; these four grading attributes help check for the authenticity of a diamond before making a purchase. Each of these C’s plays a big part in the overall appearance, quality, and price of a diamond; together, they are what give an identity to each diamond.

Having a good knowledge of the 4 C’s of a diamond would help you understand when a low-quality diamond is being showcased as a high-quality diamond, which would aid your search for a perfect diamond. 

1. Cut- the cut is the first and most important characteristic of a diamond; it covers the quality of a diamond’s angles, facets, proportions, and finishing details. The cut affects the diamond’s beauty, sparkle, and overall aesthetics; it is what differentiates one diamond from another.

The cut is what determines how the diamond interacts with light; this is further explained in three terms which is brilliance (this involves how much it sparkles in the light), dispersion (this involves how the light rays break down into spectrum colors), and scintillation (which involves how the colors seen on the diamond move inside when the gem is exposed to light).

The diamond cut is extremely important, which is why an expert is usually called to review it carefully, there are also different grading systems for diamonds used by different diamonds retailers, but the widely accepted grading system is that of the Gemological Institute of America (GIA) which grades diamonds on a scale of Ideal, Excellent, Very Good, Good, Fair, and Poor. The higher the grade of the diamond, the more expensive it would be; the ones with Excellent and ideal grades are diamonds with great proportions and angles.

2. Color- the colorlessness of a diamond affects the quality and price; when we picture diamonds, it is usually the colorless and sparkling image we have in mind, so the more colorless it is, the more expensive it would be. 

The GIA grading scale starts from D to the lowest grade, Z, the D being the grade for the most colorless and the Z containing some noticeable brown or yellow tint. When checking for colorlessness in a diamond, you should carefully observe the diamond well or seek the help of an expert to avoid purchasing a fake diamond or a diamond that interferes with the reflection of light.

3. Clarity- the clarity of a diamond affects the light that passes through the diamond. If it contains blemishes and inclusions, it disrupts the light passage and makes the diamond dull.

The clarity grading is grouped into two terms: blemishes and inclusions. The blemishes include the external impurities of the diamond gotten due to wear, tear, and the processes involved in cutting a diamond. These external impurities could be scratches across the gem’s table, dots on the gem’s surface, tiny abrasions along the faucet corner, and tiny chip-like cuts on the surface.

While the inclusions involve the impurities that come with the diamonds from underneath the Earth, they are usually minerals, feather fractures inside the gem, crystals, cavity spaces left after polishing the diamonds, etc.

 The GIA grading system for clarity includes FL (Flawless), IF (Internally Flawless), VVS1 (Very, Very Slightly Included 1), VVS2 (Very, Very Slightly Included 2), VS1 (Very Slightly Included 1), VS2 (Very Slightly Included 2), SI1 (Slightly Included 1), SI2 (Slightly Included 2), I1 (Inclusions 1), I2 (Inclusions 2) with the FL and IF is the highest grading for clarity and the SI1, SI2, and Included (I1 and I2), being on the average to low rating on the scale.

The fewer the blemishes and inclusions, the higher the price of the diamond, so when checking for clarity, look for eye-clean diamonds and ask for a confirmation from an expert.

4. Carat- this involves the overall weight of the diamond, and this weight is determined by how well the other 3 C’s are balanced. Most people may think a high carat size automatically means a high-quality Diamond which isn’t true. Rather than focusing on the carat size, you should focus on the overall appearance, cut, and brilliance of the diamond because even when a diamond has a higher carat, it is possible that the quality would look dull if the cut grade is low.

When you fully understand the 4 C’s, it becomes easier to know what you’re looking for in a diamond and hard for you to be tricked when making a purchase.

How To Tell If A Diamond Is Real With A Flashlight?

Diamonds are gemstones known to sparkle beautifully when exposed to light; even fake and real diamonds would sparkle under light, but it is the way it sparkles that would differentiate the fake from the real. Real diamonds sparkle with more brilliance; they reflect light uniquely by showing a gray and white color and a rainbow color on the surrounding surface.

The flashlight test is really easy to do all you’ll need is a light source, either a flashlight or your cellphone torch.

Start by holding the torch vertically, so the torch points upwards, then place the stone upside down on the torch lens.

Carefully observe the light that passes through the flashlight into the stone, so you’ll see if it reflects a rainbow color on the surface where the beam from the flashlight passes through the stone; the rainbow color shouldn’t be inside the diamond.

Diamonds have a high refractive index, making it possible for them to separate the normal white light coming into the diamond into different colors like a rainbow reflected on the surface surrounding the diamond.

A fake diamond, on the other hand, would not have a rainbow reflection on the surface surrounding the diamond because it lacks the refractive index of a real diamond; if you use cubic zirconia for this test, you’ll notice the difference; the rainbow color would be seen inside the diamond and not reflected outside.


Diamonds are famous, beautiful, and expensive gemstones with many uses. The aid of technology has made it possible for diamonds to be manufactured and sold for cheaper rates; however, to avoid getting a lab-created diamond in place of the real one, there are some factors to consider and many easy tests like the flashlight test to help in proving the authenticity of your diamond. If you’re still unsure after carrying out the flashlight test, consider trying other easy and quick tests like the water test, heat probe test, fog test, etc.